Urethral pudendal afferent-evoked bladder and sphincter reflexes in decerebrate and acute spinal cats

Shefchyk, S. J.; Buss, Robert R.

doi:10.1016/s0304-3940(98)00155-4

Cited by 70 publications

(71 citation statements)

References 9 publications

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“…Following acute SCT, the response to CSN branch stimulation was reduced to transient low pressure increases in bladder pressure ( Figure 7A), which corresponded to the responses generated by urethral sensory (urSPud = CSN) stimulation in SCT cats (Shefchyk and Buss, 1998). That robust sustained bladder contractions could not be evoked in the acute SCT cat indicated this low frequency pudendo-vesicle reflex is associated with the Aδ afferent fiber mediated spino-bulbo-spinal micturition reflex (Barrington, 1931.…”

Section: Sustained Bladder Contractions Evoked By Pudendal Afferentsmentioning

confidence: 88%

“…Conversely, activation of an excitatory pudendo-vesicle response has been studied as a means of restoring functional micturition (i.e., bladder emptying) in spinal intact and acute SCI , Gustafson, et al, 2003, Shefchyk and Buss, 1998, and chronic SCI cats (Tai, et al, 2006). Electrical stimulation of the pudendal nerve at 20 -50 Hz evoked robust sustained bladder contractions and voiding.…”

Section: Introductionmentioning

confidence: 99%

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Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Yoo

Woock

Grill

2008

Experimental Neurology

114

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Bladder contractions evoked by pudendal nerve stimulation in both spinal intact and spinal transected cats support the possibility of restoring urinary function in persons with chronic spinal cord injury (SCI). However, electrically evoked bladder responses in persons with SCI were limited to transient contractions at relatively low pressures. This prompted the present study, which presents a detailed quantification of the responses evoked by selective stimulation of individual branches of the pudendal nerve at different stimulation frequencies. In spinal intact cats anesthetized with α-chloralose, selective frequency dependent electrical activation of the sensory (2 Hz ≤ f ≤ 50 Hz), cranial sensory (f ≤ 5 Hz), dorsal genital (f ≥ 20 Hz) and rectal perineal (f ≤ 10 Hz) branches of the pudendal nerve evoked sustained bladder contractions dependent on the stimulation frequency. Contractions evoked by selective electrical stimulation resulted in significant increases in voiding efficiency compared to bladder emptying by distension evoked contractions (p ANOVA < 0.05). Acute spinal transection abolished reflex bladder contractions evoked by low frequency stimulation of the cranial sensory or rectal perineal branches, whereas contractions evoked by high frequency stimulation of the dorsal genital branch remained intact. This study presents evidence for two distinct micturition pathways (spino-bulbo-spinal vs. spinal reflexes) activated by selective afferent pudendal nerve stimulation, the latter of which may be applied to restore bladder function in persons with SCI. Keywords electrical stimulation; cranial sensory nerve; deep perineal branch; lower urinary tract physiology; external urethral sphincter; spinal cord injury; pudendo-pudendal reflex; spinal-bulbo-spinal; prostatic urethra; dorsal nerve of penis

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Section: Sustained Bladder Contractions Evoked By Pudendal Afferentsmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Yoo

Woock

Grill

2008

Experimental Neurology

114

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“…Fluid flow through the urethra activates pudendal afferents (56), and this flow-driven activation can elicit detrusor contractions and facilitate micturition (2,44,48). Furthermore, electrical stimulation of pudendal urethral afferents in the cat (5,49) and human (21) elicits detrusor contraction, and these responses are preserved following decerebration and acute and chronic spinal cord transection (SCT; 5,7,49,52). Conversely, activation of pudendal afferents can also inhibit detrusor contractions (33,50), and electrical stimulation of genital afferents inhibits the micturition reflex in humans with spinal cord injury (SCI), multiple sclerosis, Parkinson's disease, and other conditions resulting in neurogenic detrusor overactivity (19,22,28,31,39,58,62).…”

mentioning

confidence: 99%

Activation and inhibition of the micturition reflex by penile afferents in the cat

Woock

Yoo²,

Grill³

2008

American Journal of Physiology-Regulatory, Integrative and Comp

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Woock JP, Yoo PB, Grill WM. Activation and inhibition of the micturition reflex by penile afferents in the cat. Am J Physiol Regul Integr Comp Physiol 294: R1880-R1889, 2008. First published April 23, 2008 doi:10.1152/ajpregu.00029.2008.-Coordination of the urinary bladder and the external urethral sphincter is controlled by descending projections from the pons and is also subject to modulation by segmental afferents. We quantified the effects on the micturition reflex of sensory inputs from genital afferents traveling in the penile component of the somatic pudendal nerve by electrical stimulation of the dorsal nerve of the penis (DNP) in ␣-chloralose anesthetized male cats. Depending on the frequency of stimulation (range, 1-40 Hz), activation of penile afferents either inhibited contractions of the bladder and promoted urine storage or activated the bladder and produced micturition. Stimulation of the DNP at 5-10 Hz inhibited distension-evoked contractions and increased the maximum bladder capacity before incontinence. Conversely, stimulation at 33 and 40 Hz augmented distension-evoked contractions. When the bladder was filled above a threshold volume (70% of the volume necessary for distension-evoked contractions), stimulation at 20 -40 Hz activated de novo the micturition reflex and elicited detrusor contractions that increased voiding efficiency compared with distension-evoked voiding. Electrical stimulation of the DNP with a cuff electrode or percutaneous wire electrode produced similar results. The ability to evoke detrusor contractions by activation of the DNP was preserved following acute spinal cord transection. These results demonstrate a clear role of genital afferents in modulating the micturition reflex and suggest the DNP as a potential target for functional restoration of bladder control using electrical stimulation. electrical stimulation; spinal cord injury; dorsal nerve of the penis; frequency dependence RECIPROCAL COORDINATION of the urinary bladder and the external urethral sphincter (EUS) to maintain continence and produce micturition is controlled by the pontine micturition center (2, 3, 24). The spinobulbospinal micturition reflex is also subject to modulation by peripheral afferent activity (29, 30) that can influence voiding efficiency (41). The objective of the present study was to quantify the effects of genital afferents traveling in the penile component of the somatic pudendal nerve on the micturition reflex in the cat.Activation of pudendal afferent nerve fibers can engage spinal (5) and spinobulbospinal (2, 3) reflexes that are integral to the regulation of bladder function. Fluid flow through the urethra activates pudendal afferents (56), and this flow-driven activation can elicit detrusor contractions and facilitate micturition (2, 44, 48). Furthermore, electrical stimulation of pudendal urethral afferents in the cat (5, 49) and human (21) elicits detrusor contraction, and these responses are preserved following decerebration and acute and chronic spinal cord transection (SCT;...

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“…This is because the pudendal nerves contain motor pathways to the EUS and also afferent pathways mediating urethra-bladder and somato-bladder reflexes (Thor et al, 1989a, b). Low frequency electrical stimulation of afferent axons in the pudendal nerve in humans or the deep perineal nerve, a caudal branch of the pudendal nerve, in cats can initiate reflex bladder contractions and voiding (Boggs et al, 2005;Shefchyk and Buss, 1998). On the other hand, high frequency stimulation of pudendal nerve efferent axons or local application of 5% phenol solution can effectively block axonal conduction, suppress EUS contractions and in turn decrease in intraurethral pressure (Tai et al, 2004;Tsai et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Reflexes evoked by electrical stimulation of afferent axons in the pudendal nerve under empty and distended bladder conditions in urethane-anesthetized rats

Chang

Cheng

Chen

et al. 2006

Journal of Neuroscience Methods

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This study examined reflex mechanisms that mediate urinary bladder and external urethral sphincter (EUS) coordination in female Sprague-Dawley urethane-anesthetized rats under empty and distended bladder conditions. The bladder was distended either by a small balloon or a saline filled catheter inserted through the body of the bladder. Stimulation of the entire pudendal nerve elicited short latency (8-12 ms) responses in the EUS and short (3-8 ms) and long latency responses (16-20 ms) in contralateral pudendal nerve. The long latency pudendal-pudendal reflex was reduced by 36.7% in area during bladder distension with the balloon catheter. However, there was no significant change in the area of pudendal-EUS reflex during bladder distension. Peak amplitudes of both reflexes were reduced 32% by bladder distension. The effects of glutamatergic receptor antagonists on the reflexes were also examined. MK801 (0.3-5 mg/kg, i.v.), an N-methyl-D-aspartate glutamatergic receptor antagonist, markedly depressed the pudendal-pudendal reflex, but LY215490 (3 mg/kg, i.v.), an alpha-amino-5-methyl isoxazole-4-propionate antagonist, had a minimal inhibitory effect. Both glutamatergic receptor antagonists significantly suppressed the pudendal-EUS reflex. These results indicate that the EUS is innervated by multiple pathways and that glutamatergic excitatory transmission is important in the neural mechanisms underlying bladder-sphincter coordination in the rat.

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Urethral pudendal afferent-evoked bladder and sphincter reflexes in decerebrate and acute spinal cats

Cited by 70 publications

References 9 publications

Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Bladder activation by selective stimulation of pudendal nerve afferents in the cat

Activation and inhibition of the micturition reflex by penile afferents in the cat

Reflexes evoked by electrical stimulation of afferent axons in the pudendal nerve under empty and distended bladder conditions in urethane-anesthetized rats

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